Meryl Streep — the Oscar winner who’s transformed herself into Margaret Thatcher, Anna Wintour and Julia Child — will play opera legend Maria Callas in a film version of Terrence McNally’s play “Master Class” for HBO, Page Six can exclusively reveal.

Mike Nichols will direct the adaptation of the Tony-winning play about iconic diva Callas teaching students at Juilliard in 1971.

Hollywood sources say filming will begin in January after Streep tackles another juicy musical project — director Jonathan Demme and screenwriter Diablo Cody’s “Ricky and the Flash,” in which Streep plays a fading rock star who tries to reconnect with her estranged kids. “Meryl is learning the tricks of the guitar trade from none other than legendary Neil Young” for that movie, a source tells us.

“Master Class” debuted on Broadway in 1995 starring Australian actress Zoe Caldwell as Callas and co-starring Audra McDonald. Others who’ve tackled the role include Patti LuPone and Tyne Daly. In the play, Callas reminisces about her storied career and personal life, which included being dumped by Aristotle Onassis for Jacqueline Kennedy.

One review after the play’s 1995 opening said of Onassis, “The Greek multimillionaire is so rudely and viciously recollected that he virtually becomes an onstage character.” But, “For all of its gossipy tidbits, ‘Master Class’ is an unembarrassed, involving meditation on Callas’s life and the nature of her art.”